Friday, June 12, 2009 – How to Construct a Pentagon, and Why it Works

I am going to show you the construction and the reason why it works through a pdf file. I have also done the construction as avideo. After watching the video, then click on the pdf file name below to see the pdf file and an explanation for why it works.

Trigonometry and Why the Pentagon Construction Works

3 Responses to “Friday, June 12, 2009 – How to Construct a Pentagon, and Why it Works”

Max Says:
October 22nd, 2009 at 8:11 pm
Did you use this for construction of a house? I am trying to do the same but do not know where to start. Cay you help?
minkusbc Says:
October 23rd, 2009 at 9:45 pm
Yes, I used it to construct the basement of a geodesic dome that I was building. Once you have a pentagon, then bixect each of the five central angles and you get a decagon. The basement of my dome was a decagon.
Barney Sheehan Says:
July 11th, 2010 at 11:18 pm
http://www.mathhiker.com/wp-content/uploads/2009/06/why_pentagon_works.pdf

a typo in step (3) has AH = square root of 5 or 2.236067977

it should read GH = the square root of 5

later you prove AH = 2.351141009